Composite structures are used in a wide variety of applications. In aircraft construction, composites are used in increasing quantities to form the fuselage, wings, and other components of the aircraft. The wings of an aircraft are generally hollow structures that may require a smooth and dimensionally-accurate outer mold line (OML) surface. The wings may be constructed of composite skin members and may include internal components such as ribs, spars, and/or stiffeners to increase the strength and bending stiffness of the wings.
In conventional construction techniques for forming three-dimensional composite structures such as an aircraft wing, cured composite components such as wing spars may be assembled to composite skin members by mechanical fastening. The process of assembling the composite components may require the use of a large quantity of mechanical fasteners and specialized tooling for maintaining the relative positions of the composite components. Unfortunately, the process of forming cured composite components in a separate step and then later assembling such components using mechanical fasteners is a time-consuming and labor-intensive process.
A composite structure may also be formed by fitting together uncured composite components using a tool. Consolidation of the composite components may require a path for evacuation of gas from the part interior during the application of vacuum pressure to the tool. The path may also be required for resin movement when the composite material is heated to allow for uniform compaction pressure of the composite part against the tool surface.
Unfortunately, conventional composite tools require a relatively thick stack-up of materials against the surface of the composite part to provide a path for evacuation of gas. For composite parts having relatively tight geometry, the relatively thick stack-up of materials against the part surface presents challenges in applying uniform compaction pressure. Conventional methods may resort to multiple consolidation steps in an attempt to consolidate composite parts.
As can be seen, there exists a need in the art for a system and method for providing a low-thickness path for the evacuation of gas from a composite part such as during consolidation and which also allows for resin movement.